Zadanie w załączniku zad.1 i zad 4

zad.1 a)x=y 5x-y=4 więc 5y-y=4 y=1 x=1 b)y=2x+1 4x+2x+1=13 6x=12 x=2 y=5 c)5y-x=3 x=3-y 5*(3-y)-(3-y)=3 y=9/4 x=0,75 zad.4 a)3x=12 x=4 4-y=1 -y=-3 y=3 b)5y=2 y=2/5 x+2/5=2 i 2/5 x=2 c)4y-x=6 x=-6 y=0 d)a=b 2b+b=9 3b=9 b=3 e)u=4v 20v-v=10 19v=10 v=10/19 u=40/19 f)3r=s s+s=24 2s=24 s=12 3r=12 r=4